Regulation of dynamo-electrical machinery.



No. 673,345. Patented Apr. 30, l90l.

S. 8. WHEELER,

REGULATION OF DYNAMO ELECTRIGAL MACHINERY. (Application MedBept. 24, 1894.\ {lo Iodal.)

Ti l- Witnesses; Inventor,

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V UNITED STATES PATENT OFFICE.

S OHUYLER S. WHEELER, OF NEW YORK, N. Y., ASSIGNOR TO HARRY WARD LEONARD, OF EAST ORANGE, NEW JERSEY.

REGULATION OF DYNAMO-ELECTRICAL MACHINERY.

SPECIFICATION forming part of Letters Patent No. 673,345, dated April 30, 1901. Application filed September 24. 1894. Serial No. 523,911. (No model.)

To all whom it may concern.-

Beit known that I, SCHUYLER S. WHEELER, a citizen of the United States of America, residing in the city, county, and State of New York, have invented certain new and useful Improvements in Regulation of Dynamo- Electrical Machinery, of which the following is a specification.

The object is to provide means for regulating motors connected to a constant-potential feed-circuit without using so large resistancecoils as are required by methods now in use by mechanism which controls the speed of the motor without changing the potential of the main circuit and which can all be located at the point where the motor is working.

The invention consists, essentially, in controlling the drop of potential in the armature of the working motor by introducing into the circuit with the armature of the working motor in series the armature of a second or regulating motor and providing means for controlling the electromotive force of the reg-- ulating motor preferably by letting it drive a dynamo-armature; and my invention, in addition to the foregoing, consists in employing the current generated in the dynamo-armature to help drive the working motor. In practice I sometimes employ as the regulator a dynamo-motor, by which I mean a machine having motor-armature coils and dynamo armature coils mounted on the same shaft in a common field, so that the compound armature can be driven bycurrentfed through the motor-coils and current can be generated by the dynamo-coils by revolution of the armature. Sometimes, however, I use separate motor and dynamo armatures mechanically coupled together.

In the accompanying sheet of drawings, which forms a part of this specification, Figure 1 is a diagrammatic viewof my inven tion, and Fig. 2 is a similar view of a modification thereof.

In Fig. 1 the field-coils F ofthe Working motor and the field-coils F of the dynamomotor, each consisting of a single set of coils, are connected in multiple to the leads L L. The armature M of the working motor and the motor coils or armature Aof the dynamomotor and a rheostat R are connected in semotor are connected in series in a circuit 1, which is connected to the leads in multiple with respect to the field-coil circuits. The dynamo coils or armature D of the dynamories in a local circuit 2, which branches off from the circuit 1 at the brushes of the armature M.

In Fig. 2 the same reference characters are used as in Fig. 1 wherever the parts are iden- 6o tical. The differences in the two systems are 7 that in Fig. 2 there is no rheostat in the circuit with the dynamo-armatu re, that the motor and dynamo armature windings are on separate cores, and that the fields and the fieldcoils of the dynamo-motor are divided into two parts-one, F, serving as the field-coil of the motor-armature, and the other, F serving as the field-coil of the dynamo-armaturethe two coils being connected to the leads L L in multiple are through a rheostat R, by which one field can be increased and the other diminished in intensity at will.

In both figures the motors are supposed to be so connected to the circuits that currents shall traverse their armatures in the directions indicated by arrows.-

Having now briefly described the mechanical construction and electrical arrangement of the apparatus, I will discuss the principle of operation.

If two motors identical in construction and having their field-coils connected permanently with a constant-potential feed-circuit and their armatures connected to each other in series and then to the feed-circuit in multiple with respect to the field-coils are allowed to run free, each will generate counter electromotive force and the two electromotive forces will be equal and together willnearly equal the electromotive force of the feed-circuit. If the friction is the same in each, each machine will run at half-speed and the armatures will draw very little currentfrom the feed-circuit; but with the ordinary inequali- 5 ties of friction met with in practice among machines of the same size and type one motor will almost certainly run at full speed, there by generating an electromotive force nearly equal to that of the circuit and the other cannot obtain sufficient energy to revolve it It is therefore clear that if two machines arearranged as above suggested and one of them is allowed to run free and the other called upon to do work the system will not be operative; but if. one motor. is either. loaded or made to work at a disadvantage by some device that can be controlled by the operator it may be used to regulate the other motor without unduly cutting off current from it. For

example, aloadcan be thrown upon the reg'u lating-motor-and some means provided for adjusting the load, so as to slowdown the regulating-motor to any'necessary point to produce the desired speed in the working motor. This can be done by a brake, or the brushes of the regulating-motor can be, shifted or its field weakened, so that its speed will have to be greater than that of the. working motor, to produce the same counter electromotive force,

thus increasing the friction to be overcomeby the armature of the regulating-motor or practically increasing its load; but in illustrating my invention I have herein presented an arrangement-by which the work putupon the. regulating-motor to slow itdown is employed to assist the working motor. This I accomplish by the use of a dynamo-motor as the regulator. The dynamo-motor ispractically running with no load when it is running with its dynamo-armature circuit open;

but as soon as thisis closed and the machine begins to generate currentits motor-armature is being called upon to do work. The amount of current so generated is regulated by the resistance R in Fig. 1 or by regulating the fields ofthe motor and dynamo armatures of V Fig. 2 by the resistance R. or by shifting the brushes. The current generated 7 is carried throughcircuit 2 to the armature of theworking motor in a direction agreeing with the main current and helps todrive the working motor. Thus the motor-armatureof the regulating dynamo-motor can be -sloweddown to efiect an increase of the power of the working 1 motor by calling upon it to do work which assists in driving the working motor. There are. certain conditions under which the ratio between the armatures of thedynamo-motor may differ from unity, but these .in' no wise affect the principle ofthe invention. The principle is the same in Fig. 2, thedi-fference being that field-regulatorsare used to. control thework of the motor-dynamo instead ofare: sistance in its dynamo-circuit. Thus if the motor-field is strong it will give .a slow speed, and the dynamo-field being ml thedynamo will generate no current, the sameas if resist,

ance were all in its armature-circuit, andat the sametime the motor with strongv field will generate full counterelectromotive force and practically deprive the workingmotor of current fromthe. main circuit.- If', on; the other hand, the motor-field. is weak, thespeed will behigh, and as thedynamo-fieldisstronga large-current will be generated, and atfthe same time the motor-field being weak its electromotive force will be low, allowing increased electromotive force to reach the working motor from the main circuit.

It is obvious that a resistance R, such as above described as included in the circuit be- .tween the dynamo-armature of the dynamo motor and the armature of the working motor, can be used to assistthe rheostat R in the regulation of a construction like that shown in Fig. 2.

I do not claim in combination with an electric motor a counter-electromotive-force regulator consisting of asecond dynamo-electric machinewhose armature is in series with the motor to be regulatedand independent means for varying the counter electromotive force of the said seconddynamoaelectricmachine, as I am not the first inventor thereof;

' WhatI claim is l l. a The combination of ashunt-wound work; ing, motor and ashunt-wound regulating mo tor, the armatures. of the, two motors being connected; in series to thefeed-circuit, and means for controlling the counterelectromm tive force of the regulating-motor toregul'ate the working motor, substantiallyasset forth. 2. The combination of-a working motor and a regulating dynamo-motor, the armatureof the. working motorbeing connected to the feed circuitin series with the, motor-armature of the dynamo-motor, and-being connected in a shunt-circuit in ,series. with a-rheostat and the dynamo-armature of the ,dynamo;motor, subs,tantially as set forth. i

3. The combination of a working motor,- and a regulating dynamo-motor, a switch for simultaneously. and inversely varying, the strength of the fieldsin-w-hich the armatures of the dynamo-motor revolve, substantially as described.

4. The combinationof aworking motor and I I Io a translating device connected acrosson e-of said windings, andmeans forinverselyvarying the electromotive forces oi said windings,

substantially as set forth.

6.. The combination with a source, of elec tric energy, of two electromotive.- force-pro;

d ncing windings connected with said source,

a. translating device. connectedacross one of said-windings, and means forsimultaneollsly andr inversely varying, the electromotive iorces .of 7 said windings, substantially as set orth. i

7. The combination with a source of elec-,

tric energy, of two dynamo-electric machines connected with said source, a translating device connected across the armature-terminals of one of said machines, and means for inversely varying the fields of said machines.

8. The combination with a source of electric energy, of two dynamo-electric machines connected with said source, a translating device connected across the armature-terminals of one of said machines, and means for simultaneously and inversely varying the fields of said machines.

9. The combination with a source of electric energy, of two dynamo-electric machines connected with said source, the field-magnets of said machines being connected in multiple across said source, a translating device connected across the armature-terminals of one of said machines, and means for inversely va rying the fields of said machines.

10. The combination with a source of electric energy, of two dynamo-electric machines connected with said source, the field-magnets of said machines being connected in multiple SCHUYLER s. WHEELER.

In presence of BELLE J. HAMILTON, A. L. DOREMUS. 

